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Finding lines with a regular expression, replacing them with blank lines


 
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# 1  
Old 05-22-2012
Finding lines with a regular expression, replacing them with blank lines

So the tag for this forum says all newbies welcome...
All I want to do is go through my file and find lines which contain a given string of characters then replace these with a blank line. I really tried to find a simple command to do this but failed.

Here's what I did come up with though:

Code:
sed -e 's/REGEXP[^ ]*/MARKER/g' -e 's/[^ ]*MARKER//g' in.txt > out.txt

So I find a REGEXP, replace that and the rest of the line with "MARKER", then I replace the start of the line, including "MARKER" with nothing, thus leaving behind a blank entry...

I think this has worked... Better method please?!
# 2  
Old 05-22-2012
Hi Golpette,

It would easier to help if you can provide input data.
# 3  
Old 05-22-2012
if you make the pattern space the entire line, you can do it in 1 shot.

Code:
[mute@geek /proc]$ printf '%s\n' foo bar baz | sed 's/ar//'    #we want to find "ar"
foo
b
baz
[mute@geek /proc]$ printf '%s\n' foo bar baz | sed '/ar/d'     #delete the line
foo
baz
[mute@geek /proc]$ printf '%s\n' foo bar baz | sed 's/.*ar.*//'    #replace with nothing (blank)
foo
 
baz

 

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